As materials used for automotive lamp peripheral parts, mainly thermosetting resins such as unsaturated polyester resin BMCs (bulk molding compounds) or aluminum have conventionally been used broadly. Although thermosetting resins such as unsaturated polyester resin BMCs are superior in the light weight to aluminum, since their specific gravities exceed 2.0, more weight reduction thereof is demanded. Thermosetting resins such as unsaturated polyester resin BMCs have also problems including the complexity of postprocessing work of molded articles and the working environmental pollution due to dusts. Therefore, the conversion is progressing from thermosetting resins such as unsaturated polyester resin BMCs and aluminum toward thermoplastic resins such as polyphenylene ether, polyether imide and high heat-resistive polycarbonate as materials used for automotive lamp peripheral parts. In these applications, there are not a few cases where a high heat resistance, and a high rigidity and the surface smoothness of molded articles are required.
Polyphenylene ether resins have a variety of properties including being excellent in mechanical properties, electric properties, acid resistance, alkali resistance and heat resistance, and being low in water absorption and good in dimensional stability. Hence, polyphenylene ether resins are broadly used as materials for household appliances, OA devices, business machines, information equipment, automobiles and the like.
A usual method of improving heat resistance and rigidity of thermoplastic resins including polyphenylene ether resins is a method of adding inorganic fillers such as glass fibers, carbon fibers, mica and talc, but since the method remarkably damages the toughness, which the resins have intrinsically, and the surface appearance of molded articles, there are many applications in which the resins cannot be used.
There is now disclosed a technology regarding a reflecting plate for an automotive lamp, which is prepared by using a polyphenylene ether-based resin and which is excellent in heat resistance and hydrolysis resistance (for example, see Patent Document 1).
For a polyphenylene ether resin, there is disclosed a technology of imparting a high rigidity and holding a toughness intrinsic to the resin and a surface gloss (for example, see Patent Document 2). The technology is specifically one in which an inorganic filler surface treated with a silane compound and a thermoplastic elastomer modified with a specific functional group are added to a polyphenylene ether resin.